From: Jason Gunthorpe Subject: Re: [PATCH v3 0/5] mm/hmm/nouveau: add PMD system memory mapping Date: Fri, 10 Jul 2020 16:27:04 -0300 Message-ID: <20200710192704.GA2128670@nvidia.com> References: <20200701225352.9649-1-rcampbell@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20200701225352.9649-1-rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ralph Campbell Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jerome Glisse , John Hubbard , Christoph Hellwig , Andrew Morton , Shuah Khan , Ben Skeggs List-Id: nouveau.vger.kernel.org On Wed, Jul 01, 2020 at 03:53:47PM -0700, Ralph Campbell wrote: > The goal for this series is to introduce the hmm_pfn_to_map_order() > function. This allows a device driver to know that a given 4K PFN is > actually mapped by the CPU using a larger sized CPU page table entry and > therefore the device driver can safely map system memory using larger > device MMU PTEs. > The series is based on 5.8.0-rc3 and is intended for Jason Gunthorpe's > hmm tree. These were originally part of a larger series: > https://lore.kernel.org/linux-mm/20200619215649.32297-1-rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org/ > > Changes in v3: > Replaced the HMM_PFN_P[MU]D flags with hmm_pfn_to_map_order() to > indicate the size of the CPU mapping. > > Changes in v2: > Make the hmm_range_fault() API changes into a separate series and add > two output flags for PMD/PUD instead of a single compund page flag as > suggested by Jason Gunthorpe. > Make the nouveau page table changes a separate patch as suggested by > Ben Skeggs. > Only add support for 2MB nouveau mappings initially since changing the > 1:1 CPU/GPU page table size assumptions requires a bigger set of changes. > Rebase to 5.8.0-rc3. > > Ralph Campbell (5): > nouveau/hmm: fault one page at a time > mm/hmm: add hmm_mapping order > nouveau: fix mapping 2MB sysmem pages > nouveau/hmm: support mapping large sysmem pages > hmm: add tests for HMM_PFN_PMD flag Applied to hmm.git. I edited the comment for hmm_pfn_to_map_order() and added a function to compute the field. Thanks, Jason